1. Field of the Invention
The present invention relates to patient supports for providing gravity traction to the lumbar spine.
2. Description of the Prior Art
The advantages of gravity induced lumbar reduction have been recognized, and such treatment has been advanced by Dr. Charles V. Burton, the inventor of U.S. Pat. No. 4,205,665, issued July 3, 1980; U.S. Pat. No. 4,269,179, issued May 26, 1981; and U.S. Pat. No. 4,422,452, issued Dec. 27, 1983. The basis concept of gravity lumbar reduction is the use of gravity and the patient's own body weight to produce traction. Traction in gravity lumbar reduction, as shown in the above-mentioned patents, is provided by hanging the patient on a tilt table through suspension straps attached to a vest worn around the patient's chest. The tilt table framework permits varying the force of traction by varying the inclination of the table and the patient. When the patient is upright, the maximum traction is provided on the lumbar spine. The tilt table requires a supporting framework and is cumbersome, large, and fairly expensive to make. Additionally, the vests for supporting the patient, which are shown in U.S. Pat. Nos. 4,269,179 and 4,422,452 engage the patient's rib cage, and are designed to support a patient only through the vest engaging the rib cage.
U.S. Pat. No. 4,269,179 illustrates a vest on a patient that is resting on a tilt table in the form of an inclined board suspended from a metal frame. The inclination of the board is used for controlling the force of traction on the patient and thus a special board and board support are required. U.S. Pat. No. 4,269,179 also shows a flexible or non-rigid vest material that is designed to provide a conforming fit around the patient's torso. The vest is supposed to conform to the contour of the patient's rib cage for increased comfort.
U.S. Pat. No. 4,422,452 relates to a traction vest that has a flexible and cushioned insert that acts directly against the torso of a patient.
Additional developments in relation to traction apparatus of this general type are shown in U.S. Pat. Nos. 4,524,763, issued June 25, 1985, which utilizes an inclined support board and a vest that goes around the torso of a patient. The board is made on a frame that can be folded.
A vertical traction support belt is shown in U.S. Pat. No. 4,396,012, issued Aug. 2, 1983. The belt has a synthetic rubber material on the inside. The belt fastens around the torso of the patient to support the patient in much the same manner as that disclosed in the previous mentioned Burton patents.
A therapeutic traction apparatus that provides for supporting a patient on horizontal bars is shown in U.S. Pat. No. 3,896,798.
In each of the vest type and belt type prior art devices, the most frequent adverse affect is chest discomfort which translates into contraction of the trunk muscles that invariably counteracts the force of gravity. Gravity lumbar reduction is also difficult to carry out for those patients with any respiratory illness since the support vests act only through the chest. Even in patients that are in general good health, chest compression limits the angle of the tilt table and thus the traction force that can be tolerated. Additionally, the costs involved in present upright gravity lumbar traction systems are substantial. The vests tilt tables add considerable expense and make it quite cumbersome. This limits the use of the apparatus.